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Evolutionary dynamics of Enterococcus faecium reveals complex genomic relationships between isolates with independent emergence of vancomycin resistance

Enterococcus faecium, a major cause of hospital-acquired infections, remains problematic because of its propensity to acquire resistance to vancomycin, which currently is considered first-line therapy. Here, we assess the evolution and resistance acquisition dynamics of E. faecium in a clinical cont...

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Autores principales: van Hal, Sebastiaan J., Ip, Camilla L. C., Ansari, M. Azim, Wilson, Daniel J., Espedido, Bjorn A., Jensen, Slade O., Bowden, Rory
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Microbiology Society 2016
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5049587/
https://www.ncbi.nlm.nih.gov/pubmed/27713836
http://dx.doi.org/10.1099/mgen.0.000048
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author van Hal, Sebastiaan J.
Ip, Camilla L. C.
Ansari, M. Azim
Wilson, Daniel J.
Espedido, Bjorn A.
Jensen, Slade O.
Bowden, Rory
author_facet van Hal, Sebastiaan J.
Ip, Camilla L. C.
Ansari, M. Azim
Wilson, Daniel J.
Espedido, Bjorn A.
Jensen, Slade O.
Bowden, Rory
author_sort van Hal, Sebastiaan J.
collection PubMed
description Enterococcus faecium, a major cause of hospital-acquired infections, remains problematic because of its propensity to acquire resistance to vancomycin, which currently is considered first-line therapy. Here, we assess the evolution and resistance acquisition dynamics of E. faecium in a clinical context using a series of 132 bloodstream infection isolates from a single hospital. All isolates, of which 49 (37 %) were vancomycin-resistant, underwent whole-genome sequencing. E. faecium was found to be subject to high rates of recombination with little evidence of sequence importation from outside the local E. faecium population. Apart from disrupting phylogenetic reconstruction, recombination was frequent enough to invalidate MLST typing in the identification of clonal expansion and transmission events, suggesting that, where available, whole-genome sequencing should be used in tracing the epidemiology of E. faecium nosocomial infections and establishing routes of transmission. Several forms of the Tn1549-like element–vanB gene cluster, which was exclusively responsible for vancomycin resistance, appeared and spread within the hospital during the study period. Several transposon gains and losses and instances of in situ evolution were inferred and, although usually chromosomal, the resistance element was also observed on a plasmid background. There was qualitative evidence for clonal expansions of both vancomycin-resistant and vancomycin-susceptible E. faecium with evidence of hospital-specific subclonal expansion. Our data are consistent with continuing evolution of this established hospital pathogen and confirm hospital vancomycin-susceptible and vancomycin-resistant E. faecium patient transmission events, underlining the need for careful consideration before modifying current E. faecium infection control strategies.
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spelling pubmed-50495872016-10-04 Evolutionary dynamics of Enterococcus faecium reveals complex genomic relationships between isolates with independent emergence of vancomycin resistance van Hal, Sebastiaan J. Ip, Camilla L. C. Ansari, M. Azim Wilson, Daniel J. Espedido, Bjorn A. Jensen, Slade O. Bowden, Rory Microb Genom Standard Enterococcus faecium, a major cause of hospital-acquired infections, remains problematic because of its propensity to acquire resistance to vancomycin, which currently is considered first-line therapy. Here, we assess the evolution and resistance acquisition dynamics of E. faecium in a clinical context using a series of 132 bloodstream infection isolates from a single hospital. All isolates, of which 49 (37 %) were vancomycin-resistant, underwent whole-genome sequencing. E. faecium was found to be subject to high rates of recombination with little evidence of sequence importation from outside the local E. faecium population. Apart from disrupting phylogenetic reconstruction, recombination was frequent enough to invalidate MLST typing in the identification of clonal expansion and transmission events, suggesting that, where available, whole-genome sequencing should be used in tracing the epidemiology of E. faecium nosocomial infections and establishing routes of transmission. Several forms of the Tn1549-like element–vanB gene cluster, which was exclusively responsible for vancomycin resistance, appeared and spread within the hospital during the study period. Several transposon gains and losses and instances of in situ evolution were inferred and, although usually chromosomal, the resistance element was also observed on a plasmid background. There was qualitative evidence for clonal expansions of both vancomycin-resistant and vancomycin-susceptible E. faecium with evidence of hospital-specific subclonal expansion. Our data are consistent with continuing evolution of this established hospital pathogen and confirm hospital vancomycin-susceptible and vancomycin-resistant E. faecium patient transmission events, underlining the need for careful consideration before modifying current E. faecium infection control strategies. Microbiology Society 2016-01-19 /pmc/articles/PMC5049587/ /pubmed/27713836 http://dx.doi.org/10.1099/mgen.0.000048 Text en © 2016 The Authors http://creativecommons.org/licenses/by/3.0/ This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/).
spellingShingle Standard
van Hal, Sebastiaan J.
Ip, Camilla L. C.
Ansari, M. Azim
Wilson, Daniel J.
Espedido, Bjorn A.
Jensen, Slade O.
Bowden, Rory
Evolutionary dynamics of Enterococcus faecium reveals complex genomic relationships between isolates with independent emergence of vancomycin resistance
title Evolutionary dynamics of Enterococcus faecium reveals complex genomic relationships between isolates with independent emergence of vancomycin resistance
title_full Evolutionary dynamics of Enterococcus faecium reveals complex genomic relationships between isolates with independent emergence of vancomycin resistance
title_fullStr Evolutionary dynamics of Enterococcus faecium reveals complex genomic relationships between isolates with independent emergence of vancomycin resistance
title_full_unstemmed Evolutionary dynamics of Enterococcus faecium reveals complex genomic relationships between isolates with independent emergence of vancomycin resistance
title_short Evolutionary dynamics of Enterococcus faecium reveals complex genomic relationships between isolates with independent emergence of vancomycin resistance
title_sort evolutionary dynamics of enterococcus faecium reveals complex genomic relationships between isolates with independent emergence of vancomycin resistance
topic Standard
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5049587/
https://www.ncbi.nlm.nih.gov/pubmed/27713836
http://dx.doi.org/10.1099/mgen.0.000048
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